Network service providers typically deploy one or more servers to manage authentication, authorization, and accounting (AAA) functionality for networks that offer services to one or more subscribers. The protocol most commonly used by the servers to communicate with clients is the Remote Authentication Dial In User Service (RADIUS) protocol. The RADIUS protocol is described in Carl Rigney et al., “Remote Authentication Dial In User Server (RADIUS),” Network Working Group of the Internet Engineering Task Force (IETF), Request for Comments 2865, June 2000, which is incorporated by reference herein in its entirety (referred to hereinafter as “RFC 2865”).
To request access to a service, a subscriber connects to a network access server (NAS) that acts as a gateway to the service as provided by a service provider network (or the Internet). Often the NAS is a RADIUS client configured to communicate with a RADIUS server for the service provider network using the RADIUS protocol. As such, the NAS confirms that the subscriber is authentic and is authorized to access the service by requesting the RADIUS server to validate the access request from the subscriber. Upon validating an access request, the RADIUS server responds to the NAS with a RADIUS protocol message directing the NAS to accept the access request and establish a session enabling connectivity between the subscriber and the service provider network for the requested service.
The NAS may thereafter monitor and record statistics describing service usage by the subscriber. If configured to use RADIUS accounting, the NAS periodically outputs messages to communicate the statistics to a RADIUS accounting server using the RADIUS protocol. RADIUS accounting is described in Carl Rigney, “RADIUS Accounting,” Network Working Group of the IETF, Request for Comments 2866, June 2000, which is incorporated by reference herein in its entirety (referred to hereinafter as “RFC 2866”).